Hedge trimmer



J. E. HOLMES HEDGE TRIMMER July 14, 1953 2 Sheets-Sheet 1 Original Filed March 11, 1946 INVENTOR. JOSEPH E. HOLMES AGENTS J. E. HOLMES HEDGE TRIMMER July 14, 1953 2 Sheets-Sheet 2 Original Filed March 11, 1946 INVENTOR. JOSEPH E. HOLMES AGENTS Patented July 14, 1 953 HEDGE TRIMMER Joseph E. Holmes, Huntington Park, Califl, as-

signor. of one-half to Ester Holmes, Huntington Park,- Calif.

Substituted for abandoned application Serial No.

653,529, Marclrll, 1946. 'lhisapplication tember 2, 1952; Serial No. 307,494

Sep-

7 Claims. (01. 30444) The present invention. relates generally to a hedge trimmer and more particularly to a hedge trimmer which will operate efficiently on all kinds of shrubbery or the like. i g

This is a substitute application for my abancloned application, Serial bio-653,529, filed March 11, 1946.

The primary object of this invention is to provide a hedge trimmer which will out small limbs and large limb-s simultaneously, thus being adapted for use on all kinds of hedges, shrubbery or the like.

Another object of this invention is to provide a hedge trimmer of the type described having a rotating cutter of substantially circular form, of a larger limb, and the action of the specially but v g Sh elements as. Well as designed toothed elements in preventing'shimmying elements which operate either alternately or ing or undue vibration during use.- simultaneously. Referring now to the drawing in detail, Fig. 1 Another object of this invention is to provide shows a hedge trimmer in which a ledgeror staa h d e t mm of th type described having a tionary cutter blade in is secured to a housing I? ledger or stationary blade consisting of a p1uby means-of screws It, said ledger or'stationar'y rality of fingers or guides which will hold the blade having about its periphery a plurality of twigs and limbs of the hedge in position while fingers or guides l8.- The guides are small in the rotating cutter severs-them, the above menwidth at their outer edges'and taper gradually tioned shearing and sawing elements being functo a greater width at their roots thus forming tional throughout the major portion of thecomslots of substantially V-shapedform. as indicated plete periphery of the ledger plate. r at I 8. The shear edges IQ of the guides I6 ex-' Another object of this invention is to provide tend radially while the opposingedges of th slots a hedge trimmer of the type described in which l8 are non-radially disposed. "The housing 12 the rotating cutter is driven by means of anele'cis attached to a handle 20 having at' its end a tric motor, or similar power unit, at high speed hand grip 22 containing a switch 24 operated by but without the usual tendency to jam or to vi means of a trigger 26. Said switch controls a'fiow brate excessively. e of electrical current in wires-28 which are car- Another object of this invention and this disriedwithin the handle 20, emerging from said closure, ancillary to the immediately preceding handle at groimnet 30 and extended to the motor obj ect,- is to teach the best known mode of carry- 32. The motor 32 is provided with an externally ing the invention into actual practice. I screw threaded boss 34 engaging an internally Another object of this invention is to provide screw threa'ded socket portion in housing. The a hedge trimmer which is adapted for fabricationshaft of motor. 32. is similarly externally Screw from many different materials'so that the choice 40 threadedia'nd engages-"with an internally screw of material can be according to the dictates of threaded portion 38 of a drive shaft whi h i availability and price considerations, the exact rotatably mounted in housing l2 by means of a sizes and proportions being matters easilydeterbearing 42. A drive plate 44 is secured to the mined to suit particular conditions and needs. drive shaft 40 by means of a key 46 ehgagd in Finally, it is an object to provide a hedge trima slot 48- of the hub 50. A rotating cutter 52 mer of the aforementioned character which is is centrally located on the drive plate/34 by simple, safe and convenient to operate, andwhich means of a hubv extension 54 and is retained in will give generally efficient and durable service. position by means of a clamp plate 56' secured to With these and other objects definitely in View, a screw threaded portion 58 of the drive shaft this inventionconsists in the novel construction, 40; The rotating cutter 52 has about its combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out m-the claims, and illustrated in the drawing which forms a material part of this disclosure andwu wherein similar characters of reference indicate similar or identical elements and portions throughout the specific'aticnand throughout the views of the drawing, and in which:

Fig. l is a plan view of the hedge trimmer with the power unit omitted for clarityu- J Fig. 2 is a setcional view taken on the line 2-2 of Fig. 1." w W Fig. 3 is a fragmentary sectional view taken'on the'line 3--3 of'Fig. 2. g I Fig. 4 is an-inverted plan view of the working section of the hedge trimmer, the figure being proposed as illustrating the shearing action in connection with small limbs or twigs, the sawin ery four equally spaced projections or individual teeth 60, each'provided with a'pluralit-y ofsaw teeth 62 commencingat a shearedgetfi and extending along the outer edge of the segment',' jit being noted that the'radius ofeacl projection 3 or tooth 60 is graduall increased from the shear edge 64 to a trailing portion 66 the edge of which defines an arc of gradually decreasing radius to a point 68 on the basic radius edge of the rotating cutter.

To operate the hedge trimmer the handle is grasped near the housing I2 at a position indicated by the numeral 12, a finger being extended through the hole 13 if desired. The other hand should grasp the hand grip 22 and the rotating cutter set in operation by depressing the trigger 26 of the switch 24. When the hedge trimmer is applied to the shrubbery to be trimmed a number of limbs will enter the slots 18. Small limbs will be forced to the bottom of the slots as indicated at 14 in .Fig. 4 and will be cut off due to the shearing action between the shear edge 64 and the shearing edges is of the ledger plate I E. Larger limbs will enter the slots partially as indicated at I6 in Fig. 4 and will be cut by the saw 62. Due to the fact that the saw teeth 62 are positioned on an arc of gradually increasing radius each tooth will cut successively deeper into the limb thus relieving any sudden loads on the motor which would occur if too deep a out were attempted at one time. When all the saw teeth of one projection or individual tooth 60 have passed through the limb completing their cutting action, the limb will be engaged by the trailing portion 66 as indicated at 18 in Fig. 4, thus momentarily delaying the tendency of the limb to fall further into the slot. It has been found in practice that this delaying action at a critical point in the rotation of the cutter will prevent jamming of the cutter as would take place if the limb was allowed to fall directly into the path of the shear edge :64. The cutter 52 is driven by the electric motor at a high R. P. M. and the mass and inertia of the trimmer is sufficient to prevent jamming of the cutter since the time interval between successive contacts of the pro- Jection or tooth is small and the trailing portions 16 greatly reduce the tendency for the limb to enter between the projection or tooth. Nevertheless, the advantage of a wide circumferential distance. between teeth 60 is preserved, allowing the smaller, more resilient limbs and twigs ample opportunity to reach the ledger or stationary cutter blade at the basic radius line 10 so that they will be sheared by the shear edges 64, while the number of saw teeth on the cutter is reduced so that only a small motor is enabled to do the required work. It must be pointed out that this action constitutes a distinct improvement over the action of the hedge trimmer described in the aforementioned abandoned application.

It will be obvious that the power unit of this hedge trimmer need not be limited to an electric motor but may be of any suitable type such as a compressed air motor or a gasoline engine. 7

The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawing and the above recited objects. It will be obvious that all said objects are amply achieved by this invention.

Further description would appear to be unnecessary.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. In a hedge trimmer of the class described, the combination of a stationary cutter blade having a plurality of converging notched teeth about its periphery, a revolving cutter having a plurality-or ind'mldual teeth revolubly mounted relatively to said stationary cutter and contiguous therewith whereby the teeth of said revolving cutter pass adjacent the teeth of said stationary cutter, .the shearing edge of the teeth of said stationary cutter being substantially in radial alignment with the axis thereof, the leading edge of the teeth of said revolving cutter being substantially in radial alignment with the axis thereof, and having saw teeth at the extremities thereof, the roots of which are outwardly of the roots of a said individual teeth.

2. In a hedge trimmer of the class described, the combination of a stationary cutter blade having a plurality of notched teeth about its periphery, a revolving cutter having a plurality of teeth revolubly mounted relatively to said stationary cutter and contiguous therewith whereby the teeth of said revolving cutter pass adjacent the teeth of said stationary cutter, the leading edges of the teeth of said revolving cutter being substantially parallel with the shearing edge of the. teeth of said stationary cutter, each individual tooth of said revolving cutter having a plurality of .saw teeth at its outer edge and extending radially beyond the root of said saw teeth toward the axis of said revolving cutter.

3. .In a hedge trimmer of the class described, the combination of a stationary cutter blade having a plurality of notched teeth about its periphery, a revolving cutter having a plurality of teeth .revolubly mounted relatively to said stationary cutter and contiguous therewith whereby the teeth of said revolving cutter pass adjacent the teeth of said stationary cutter, the leading edges .of the teeth of said revolving cutter being substantially parallel with the shearing edge of the teeth of said stationary cutter, each individual tooth of saidrevolving cutter having a plurality of saw teeth at its outer edge and extending radially beyond the root of said saw teeth toward the axis of said revolving cutter, said saw teeth being of diiIerent radially disposed extension from the axis of the revolving cutter whereby each successive adjacent saw tooth extends slightly further radially from the leading edge of the individual teeth of said revolving cutter toward the trailing edge of said individual teeth.

4. In a hedge trimmer of the class described, the combination of a stationary cutter blade having a plurality of notched teeth about its periphery, a revolving cutter having a plurality of teeth revolubly mounted relatively to said stationary cutter and contiguous therewith whereby the teeth of said revolving cutter pass adjacent the teeth of said stationary cutter, the leading edges of the teeth of said revolving cutter being sub stantially parallel with the shearing edge of th teeth of said stationary cutter, each individual tooth of said revolving cutter having a plurality of saw teeth at its outer edge, and extending radially beyond the root of saidsaw teeth toward the axis of said revolving cutter, said saw teeth being of difierent radially disposed extension from .the axis of the revolving cutter whereby each successive adjacent saw tooth extends slightly farther radially from the leading edge of the individual teeth of the said revolving cutter toward the trailing edge of said individual teeth. ,a motor in axial alignment with said revolving cutter, a frame interconnecting said'motor and said stationary cutter, a shaft for said revolving cutter in operativerelation with said motor and a a pair of clamping plates secured on opposite sides of the revolving cutter in connection with said shaft. f

5. In a hedge trimmer of the class described, the combination of a substantially circular stationary cutterhaving a plurality of notched teeth about the periphery thereof having shearing edges, a revolving cutter contiguous with said stationary cutter and having a lesser number of individual teeth than the stationary cutter, the leading edges of said individual teeth being 'parallel with said shearing edges and adapted to cooperate with the shearing edges of the teeth of said stationary cutter, the outer edges of said individual teeth bein provided with a plurality.

of saw teeth each radially extended slightly beyond the adjacent saw tooth whereby the saw tooth at the leadingedge of the individual tooth of said revolving cutter is on a shorter radius than the saw teeth nearing the trailing edge of 6. Apparatus accordingto claim 1 and wherein said revolving cutter has a basic radius edge,

each individual tooth of said revolving cutter, each of said individual teeth extending inwardly 25 beyond the roots of said saw teeth.

between'said individual teeth, and said individual I teeth include trailing portions having smoothedge faces extending from the rearmost of said saw teeth to said basic radius edge.

7. Apparatus according to claim 6 and wherein said smooth edge faces of the trailing portions define arcs of constantlyfdecreasing radius from said rearmost saw teeth to said basic radius edge.

' JOSEPH E. HOLMES.

References Cited in the'file of this patent UNITED STATES PATENTS I Date.

Great Britain Oct. 715, 1946 

